There is significant industry research and development in the area of ad-hoc networking. The term “ad-hoc” (or “spontaneous”) has been applied to networks that are formed and deformed on-the-fly, without the need for system administration. An ad-hoc network is essentially infrastructure-less since there is no need for fixed base station, wires, or routers in the network. Ad-hoc network technology for example may allow people to come to a conference room and, using infrared transmission or radio frequency (RF) wireless signals, join their notebook computers or PDAs (personal digital assistant) with other conferees to a local network with shared data and printing resources. In another application, a user's ad-hoc device may communicate with home wireless devices to unlock doors, activate lights and home audio and video equipment units, adjust heating and cooling settings, and the like.
Ad-hoc networks can be mobile, standalone, or/and networked with other networks such as wide area networks or the Internet. A mobile ad-hoc network is a self-configuring network of mobile routers, connected by wireless links. Mobile ad-hoc devices are able to detect the presence of other ad-hoc devices, establish communication links with the other devices, and communicate information such as packetized digital data. Since the devices move randomly, the network topology is rapidly and unpredictably changing, so that the devices often have different views of the network, both in time (information may be outdated at some nodes but current at others) and in space (a node may only know the network topology in its neighborhood).
Due to the lack of a fixed infrastructure, nodes must self-organize and reconfigure as they move, join or leave the network. All nodes could potentially be functionally identical and there may not be any natural hierarchy or central controller in the network; many network-controlling functions are distributed among the nodes. Nodes are often powered by batteries and have limited communication and computation capabilities. The bandwidth of the system is usually limited. The distance between two nodes often exceeds the radio transmission range, and a transmission has to be relayed by other nodes (multihop technology) before reaching its destination.
Quality-of-service (QoS) routing in mobile ad hoc networks is gaining interest. To provide QoS, the protocol needs not only to find a route but also to secure the resources along the route. Because of the limited, shared bandwidth of the network, and lack of central controller which can account for and control these limited resources, nodes must negotiate with each other to manage the resources required for QoS routes. This is further complicated by frequent topology changes. Due to these constraints, QoS routing is more demanding than best-effort routing.
The use of wireless LANs is expected to increase dramatically in the future as businesses discover the enhanced productivity and the increased mobility that wireless communications can provide. New applications for mobile ad-hoc networks will continue to emerge and become an important part of the communication structure. One wireless networking protocol of significant importance due in part to its growing use in devices such as palmtop computers, personal digital assistants (PDAs), laptop computers, and Internet mobile phones is IEEE 802.11. The Mobile Ad-Hoc Networks (MANET) working group of the Internet Engineering Task Force (IETF) has been actively evaluating and standardizing routing, including multicasting, protocols.
Although 802.11 provides a reliable means of wireless data transfer, the 802.11 standard does not support QoS traffic delivery in its MAC layer. There is an 802.11 Task Group e (TGe) joint proposal to support QoS enhancements. Virtual streams having QoS parameter values including priority, data rate, delay bounds and jitter bounds, are supported. The proposal uses a point coordinator (PC) function, featuring reservation request procedures to request new bandwidth allocations. Several new data and management frames are used. New acknowledgement policies, direct station-to-station transfers, basic service set (BSS) overlap management, and dynamic wireless repeater functions are included. However, this proposal requires modification of the existing 802.11 standard, and may not support, or be supported by, legacy 802.11 devices.
Prior art is centered around the routing and signaling issues, as opposed to the datapath issues. There is no known solution to the QoS problem in mobile ad-hoc networks, and there is a need to address this problem as the use of mobile networks increases. The present invention relates to a low cost mobile ad-hoc networking device which provides a decentralized IP routing network amongst a set of mobile devices within the communication range, and can offer QoS for voice, video and data applications. The basic technology can also be applied to large scale fixed IP networks of low cost simple devices.